Relaxation in hypertrophic cardiomyopathy and hypertensive heart disease: relations between hypertrophy and diastolic function

AIM To determine the relation between the extent and distribution of left ventricular hypertrophy and the degree of disturbance of regional relaxation and global left ventricular filling. METHODS Regional wall thickness (rWT) was measured in eight myocardial regions in 17 patients with hypertrophic cardiomyopathy, 12 patients with hypertensive heart disease, and 10 age matched normal subjects, and an asymmetry index calculated. Regional relaxation was assessed in these eight regions using regional isovolumetric relaxation time (rIVRT) and early to late peak filling velocity ratio (rE/A) derived from Doppler tissue imaging. Asynchrony of rIVRT was calculated. Doppler left ventricular filling indices were assessed using the isovolumetric relaxation time, the deceleration time of early diastolic filling (E-DT), and the E/A ratio. RESULTS There was a correlation between rWT and both rIVRT and rE/A in the two types of heart disease (hypertrophic cardiomyopathy: r = 0.47, p < 0.0001 for rIVRT; r = -0.20, p < 0.05 for rE/A; hypertensive heart disease: r = 0.21, p < 0.05 for rIVRT; r = -0.30, p = 0.003 for rE/A). The degree of left ventricular asymmetry was related to prolonged E-DT (r = 0. 50, p = 0.001) and increased asynchrony (r = 0.42, p = 0.002) in all patients combined, but not within individual groups. Asynchrony itself was associated with decreased E/A (r = -0.39, p = 0.01) and protracted E-DT (r = 0.69, p < 0.0001) and isovolumetric relaxation time (r = 0.51, p = 0.001) in all patients. These correlations were still significant for E-DT in hypertrophic cardiomyopathy (r = 0.56, p = 0.02) and hypertensive heart disease (r = 0.59, p < 0.05) and for isovolumetric relaxation time in non-obstructive hypertrophic cardiomyopathy (n = 8, r = 0.87, p = 0.005). CONCLUSIONS Non-invasive ultrasonographic examination of the left ventricle shows that in both hypertrophic cardiomyopathy and hypertensive heart disease, the local extent of left ventricular hypertrophy is associated with regional left ventricular relaxation abnormalities. Asymmetrical distribution of left ventricular hypertrophy is indirectly related to global left ventricular early filling abnormalities through regional asynchrony of left ventricular relaxation.

Seven years of annual pollen influx at the forest limit in the Swiss Alps studied by pollen traps: relations to vegetation and climate

Annual pollen influx has been monitored in short transects across the altitudinal tree limit in four areas of the Swiss Alps with the use of modified Tauber traps placed at the ground surface. The study areas are Grindelwald (8 traps), Aletsch (8 traps), Simplon (5 traps), and Zermatt (5 traps). The vegetation around the traps is described. The results obtained are: (1) Peak years of pollen influx (one or two in seven years) follow years of high average air temperatures during June–November of the previous year for Larix and Picea, and less clearly for Pinus non-cembra, but not at all for Pinus cembra and Alnus viridis. (2) At the upper forest limit, the regional pollen influx of trees (trees absent within 100 m of the pollen trap) relates well to the average basal area of the same taxon within 10–15 km of the study areas for Pinus cembra, Larix, and Betula, but not for Picea, Pinus non-cembra, and Alnus viridis. (3) The example of Zermatt shows that pollen influx characterises the upper forest limit, if the latter is more or less intact. (4) Presence/absence of Picea, Pinus cembra, Larix, Pinus non-cembra, and Alnus viridis trees within 50–100 m of the traps is apparent in the pollen influx in peak years of pollen influx but not in other years, suggesting that forest-limit trees produce significant amounts of pollen only in some years. (5) Pollen influx averaged over the study period correlates well with the abundance of plants around the pollen traps for conifer trees (but not deciduous trees), Calluna, Gramineae, and Cyperaceae, and less clearly so Compositae Subfam. Cichorioideae and Potentilla-type. (6) Influx of extra-regional pollen derived from south of the Alps is highest in Simplon, which is open to southerly winds, slightly lower in Aletsch lying just north of Simplon, and lowest in Zermatt sheltered from the south by high mountains and Grindelwald lying north of the central Alps.